Preparation of Core–Shell-Type Poly(ethylene glycol)-Grafted Polystyrene Resins and Their Characteristics in Solid-Phase Peptide Synthesis

Abstract

By suspension polymerization using styrene, divinylbenzene, and synthetic poly(ethylene glycol) (PEG) macromonomers, we have prepared core–shell-type resins that have a highly crosslinked polystyrene core and a PEG shell. The PEG macromonomer, which has a vinyl group and an amino group at each terminal, plays a role as a stabilizer in the suspension polymerization system. All the resins were of the bead type with a diameter of 38–150 μm. The loading capacities of the amino groups were 0.1–0.2 mmol · (g resin)−1 and the thickness of the PEG shell 2–4 μm, which was verified by cross-sectioned views of the fluorescamine-coupled beads. During coupling of amino acids in solid-phase peptide synthesis, the resin showed better yields than TentaGel resin, especially during the first coupling step. In the enzymatic cleavage reaction, the resin-bound peptides were shaved about 5–10 times more than TentaGel resin. SEM micrograph of CutiCore resin (×200).